Heretofore, inflatable cushioning devices for use with body supports, such as a mattress, sofa, seat, or the like, typically included a plurality of air cells or bladders that are inflated to support a person. The air cells provide support to the person, and can be inflated to a desired pressure level to provide the person with a predetermined level of comfort and support.
In the medical field, cushioning devices including a plurality of air cells are often used to provide different levels of support under various portions of a patient's body. For example, a mattress may include separate air cells located in the upper, middle, and lower portions of the mattress. These air cells can be inflated to different pressures to support the upper, middle, and lower portions of the patient's body with different pressures.
In hospitals which provide care to patients confined to a bed for extended periods of time, the patients often suffer from the effects of excess pressure transmitted to their bodies. As known in the medical field, continuous pressure applied to a patient's body can cause soft tissue damage. When the external pressure exerted on the patient's skin causes blood carrying capillaries to close, soft tissue degeneration may occur. This soft tissue damage may lead to the formation of pressure sores. For example, continuous pressure applied to a patient's heel can cause a pressure sore to develop on the heel. The multi-cell cushioning devices described above can be used to relieve the pressure applied to a specific portion of a patient's body. In the case of a patient's heel, for example, this may be accomplished by inflating the air cell under the patient's leg so that the heel is lifted from the mattress. Thus, the continuous heel pressure is relieved and the formation of a bed sore on the heel is prevented.
Air cushion devices typically require an external pump to inflate the air cells in the device. Alternatively, the air cushion devices are pre-inflated in the manufacturing plant and are shipped to a field location for use. A problem may develop when the atmospheric pressure at the inflation location is different from the atomospheric pressure at the field location where the device is used. For example, if the field location atmospheric pressure is lower than the atmospheric pressure at the inflation location, the air cells in the field will expand and become firmer.
Hospitals rate pressure relief support systems as "treatment products" if they sufficiently reduce the pressure upon a patient's body, reduce tissue trauma, and facilitate the healing of skin ailments, such as burns, pressure sores, etc. Typical pressure relief support systems which qualify as "treatment products" are embodied in beds which contain motors and pumps to vary the shape and pressure within the mattress. Such beds are very expensive and require the operator to undergo extensive training to learn how to use and operate the system. Furthermore, the "treatment products" often require extensive maintenance due to the failure of the numerous moving mechanical parts. Also, these complicated pressure relief support systems cannot be used on typical box spring mattress supports, and require specialized bed frames. The complicated design of these beds makes their repair very difficult, and often requires the complete replacement of the entire system for proper servicing. A further difficulty is that during power outages, these mattresses lose pressure leaving a patient on a hard surface to develop pressure sores if action is not taken. Thus, a need exists to arrive at a body support which adequately addresses these disadvantages.